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Thursday, August 22, 2002

Sexual Selection, Temperature, and the Lion's Mane

An interesting paper in tomorrow's issue of Science about the characteristics of lion manes...

The abstract:

The mane of the African lion (Panthera leo) is a highly variable trait that reflects male condition and ambient temperature. We examined the consequences of this variation in a long-term study of lions in the Serengeti National Park, Tanzania. Mane darkness indicates nutrition and testosterone and influences both female choice and male-male competition. Mane length signals fighting success and only appears to influence male-male assessment. Dark-maned males enjoy longer reproductive life-spans and higher offspring survival, but they suffer higher surface temperatures, abnormal sperm, and lower food intake during hot months of the year. Maned males are hotter than females, and males have lighter and/or shorter manes in hotter seasons, years, and habitats. This phenotypic plasticity suggests that the mane will respond to forecasted increases in ambient temperature.

Fat kids make fat adults

Children's weight up to age 20 is a good predictor of weight at age 35, according to a study published today in the American Journal of Clinical Nutrition. Children who are overweight or obese are likely to be overweight or obese as adults, as measured by body mass index (BMI).

Journal article
Press release

Procrastinators get poorer grades in college class

The worst procrastinators received significantly lower grades in a college course with many deadlines than did low or moderate-level procrastinators according to a presentation at the American Psychological Association annual meeting today.

The worst procrastinators were also more likely than others to use rationalisations - such as saying "I work best under pressure" - to justify their behaviour in school.

More information

Street parties like ant swarms

John Whitfield writes at Nature Science Update that London's Notting Hill carnival has been modelled as an ant swarm to help authorities determine how to alleviate crowding and crush spots.

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